RECOVERY OF ACETIC ACID FROM WASTE WATER BY SOLVENT EXTRACTION

Abstract

Acetic acid is a major commercial chemical with many applications in chemical industry. The same acid becomes environmentally evil when present in water-courses. Waste water streams from DMT production units,wood-pulping units, and petrochemical industries are prime sources of acetic acid ranging from 0.5 to 5 wt°10'. Presence of acetic acid in water-courses causes numerous environmental problems. Corrosion in water structures, odour problems,water toxicity; and water treatment problems are some resultS of presence of acetic acid in water. It,therefore, becomes imperative to, evolve economic and effective technologies to recover acetic acid from dilute waste water streams. Solvent extraction is one such method. This ,method is both cheap and highly effective, Traditional solvents, namely ketones, ethers, alcohols , etc. have been replaced by newer solvents namely tri-n-octylamine, tri-octyl-phosphine oxide, etc. possessing higher distribution coefficients and very limited Water solubilities. In the present study extraction behaviour was studied using tri-butylamine and tri butyl phosphate as solvents, and kerosene as diluent. Experiments were conducted to know the- effects.of the variables, such as, feed concentration, solvent to diluent ratio, solvent to feed ratio; and temperature on the extraction of acetic acid from waste water. For the studies synthetic 'samples were prepared by dissolving specified doses of acetic acid in distilled water. The results indicated that acetic acid can be effectively recovered/removed from the dilute waste water using tributyl phosphate with kerosene. It was also found that performance of tributyl phosphate at room temperature is very satisfactory.